NEW: GOP Incumbent Leads Dem Opponent In Closely-Watched Senate Race, Top Pollster Finds

Quantus Insights — one of the most accurate pollsters of  the 2024 presidential election — found incumbent Senator Susan Collins (R-ME) leading over Democratic Party opponent Troy Jackson in a race that could decide the balance of power in the U.S. Senate.

The poll, which surveyed 644 likely voters between September 14-15, used a base of 621 respondents after excluding 23 people who said they would not vote in the race. The margin of error was +/- 4.3 percentage points.

On the initial ballot test, Collins received 47.1 percent support and Jackson received 46.4 percent. An additional 1.5 percent selected someone else, while five percent were undecided.

That produced a Collins lead of 0.7 points. When leaners were included, Collins stood at 47.6 percent and Jackson at 47.4 percent, with 1.5 percent for someone else and 3.5 percent undecided, a Collins edge of 0.2 points.

Both results fall well inside the survey’s margin of error, while Quantus Insights noted that neither candidate holds a statistically clear statewide lead.

POLL: Will You Support Trump And His Candidates In The Midterms?

NEW QUANTUS INSIGHTS MAINE SENATE POLL | September 16, 2026

Our latest survey of 644 likely Maine voters finds Susan Collins and Troy Jackson essentially tied in a tight, competitive race for U.S. Senate.

📊 Maine U.S. Senate
🔴 Susan Collins (R): 47.1%
🔵 Troy Jackson (D):… pic.twitter.com/bdQREUgm8K

— Quantus Insights (@QuantusInsights) September 16, 2026

Favorability ratings were similarly close and modestly negative for both candidates. Collins was viewed favorably by 46.3 percent of respondents and unfavorably by 53.0 percent, a net rating of minus 6.7. Jackson was viewed favorably by 45.5 percent and unfavorably by 50.6 percent, a net of minus 5.1.

When breaking down the results further, Quantus found that Collins performed better among men, older voters, and rural communities. Jackson led among women, younger voters, and suburban voters. Full crosstabs can be found on the firm’s website.

Collins holds the notable distinction of being the only Republican senator from a state that Kamala Harris carried in 2024 and that has not supported a Republican presidential nominee in decades.

Jackson, a former Maine Senate president, became the Democratic nominee after Graham Platner won the June primary but withdrew in July amid controversies. Jackson was then installed by Maine Democrats at a convention in July.

Maine uses ranked-choice voting, though no independent candidate has qualified for the November 3 ballot.

Quantus Insights has previously surveyed the Maine race. In June it found a 46–45 Platner-Collins result among 870 likely voters. An earlier March survey tested hypothetical matchups before the Democratic field was settled.

The September results therefore represent the firm’s first public reading of the Collins-Jackson pairing.

RELATED: GOP Candidate Surges In Blue State Senate Race, Quantus Insights Poll Finds